Prof. Dr. Roderich Moessner & Prof. Dr. Achim Rosch

Roderich Moessner and Achim Rosch are receiving the Leibniz Prize for their outstanding contributions to research into interactive quantum systems. This field of research is one of the most exciting fields of modern solid-body physics both in terms of basic research and future applications. It is also an enormous challenge, particularly for theoretical physics.

Roderich Moessner has accepted this challenge with a focus on frustrated quantum spin systems and is considered one of the world's leading researchers in this field. He was the first person to operationalise the more than 70-year-old hypothesis of the existence of magnetic monopoles. Moessner predicted that in spin ice magnetic dipoles will decay into magnetic monopoles and simultaneously identified a system in which this effect would be observable. Approximately one year later other researchers succeeded in proving this experimentally. Moessner's work in the resonating valence bond phase in the quantum dimer model in magnetically frustrated systems was also pioneering. Roderich Moessner laid the groundwork for these later successes during his studies and doctorate at Oxford. At this time and during subsequent postdoc work in Princeton and at CNRS in Paris, he oriented himself on the international luminaries of his field. After a period as a lecturer at Oxford, in 2007 at the age of just 36 Moessner became director at the Max Planck Institute of Physics of Complex Systems in Dresden.

Achim Rosch has had tremendous success researching a broad spectrum of physical questions related to the theory of condensed materials. In addition to fundamental theoretical work, he regularly collaborates with experimental working groups. His work has led, for example, to the high-profile theory of quantum-critical points of anti-ferromagnetic metals. The experimental identification of a skyrmion lattice in helimagnets based on Rosch's theoretical analysis is likewise very significant. His work also focuses on ultracold atoms. Together with Leibniz prize recipient Immanuel Bloch, it was the first time that the fermionic Hubbard model with ultracold gases in optical lattices could be realised experimentally. Finally, Rosch received a great deal of attention for his prediction of states with negative absolute temperature. Achim Rosch studied physics in Karlsruhe where in 1997 he received his doctorate. He spent his postdoc time at Rutgers University in New Jersey before returning to Karlsruhe as the head of a DFG-funded Emmy Noether independent junior research group. In 2004 he became a professor at the University of Cologne. Since 2006 he has also been the spokesperson of a Collaborative Research Centre in Cologne.